A New Chalcone Glycoside, a New Tetrahydrofuranoid Lignan, and Anti-oxidative Constituents from the Stems and Leaves of Viburnum propinquum

A new chalcone glycoside (2) and a new tetrahydrofuranoid lignan (3), along with 12 known compounds, were isolated from the stems and leaves of Viburnum propinquum Hemsl. The structures of all isolated compounds were deduced using spectroscopic and chemical methods. Antioxidative activities of most phenolic compounds were evaluated. Compounds 1 (3,4,2',4'-tetrahydroxy-trans-chalcone), 2 (3,4,2',4'-tetrahydroxy-trans-chalcone-2'-O-beta-D-glucoside), 12 (quercetin), 13 ((+)-dihydroquercetin), and 14 (eriodictyol) showed antioxidative capacities in the DPPH and hydroxyl free-radical assays, with IC50 values of 3.80-6.12 mu g/mL, and 9.24-11.87 mu g/mL, respectively. Compounds 1, 2, 12, 13, and 14 also exhibited inhibitory activities against lipid peroxidation in rat liver homogenate, with an inhibitory rate of 10.8-39.9% at 20 mu g/mL, 38.8-57.2% at 100 mu g/mL, and 44.2-72.4% at 200 mu g/mL, respectively.